In the textile industry, various types of fibers and materials are used in the manufacture of threads, yarns, fabrics and finished materials. Three types of fabrics known to those skilled in the art include woven, nonwoven and knitted fabrics. Nonwoven materials are manufactured by means other than by weaving or knitting. Nonwoven materials are utilized in a broad and diverse range of products, such as, absorbent pads, wiping and cleaning sheets and fabrics, insulation, liners, wicks, relatively thick battings, compressed bonded battings and webs, bandages, incontinence structures , filters and the like. Woven and knitted materials typically use a thread or yarn material and are produced by using a weaving or knitting apparatus known to those skilled in these arts.
Synthetic materials and combinations of natural and synthetic materials are becoming increasingly plentiful and inexpensive. For example, fabrics coated at least on one side with film or foamed sheets made of various materials such as urethane, polyester, rubber, etc. are useful for producing light-weight, wind-resistant clothing; insulated materials; water-resistant products; etc. However, in certain characteristics, many of these materials do not compare well to natural fibers, such as, the ability to transport moisture satisfactorily, improved softness and wetting characteristics. All of these characteristics are important, and in the use of staple fibers, the fibers must perform satisfactorily in known operations such as blending, carding, roving, drawing, spinning, weaving, knitting, bonding, heating, compressing, hydro-entangling, needle-punching, and the like. Generally, to facilitate such operations the fibers are coated with certain processing lubricants, such as those based on potassium lauryl phosphate or mineral oil. U.S. Pat. Nos. 5,372,739 and 5,677,058 disclose altering certain surface characteristics of various fibers by applying a lubricant composition having a mixture of high and low molecular weight polyethylene glycol fatty acid esters and other hydrophilic compositions. Modifications of these compositions to include various additives are also described.
Additionally, for certain useful applications, such as wet wipes and absorbent structures, liquid-transport durability is a desirable characteristic but difficult to obtain in some man-made fibers. Certain man-made fibers, and particularly those with suitable non-round cross-sections, have some initial liquid-transport characteristics which diminish after wet usage, washing or scouring. The ability of these fibers to transport liquid can in some instances diminish significantly.
Moreover, the crimping of a staple fiber by various means has been found to be an essential element in producing a certain controlled amount of fiber cohesion or resistance to pulling apart in forming carded webs. These webs of separated fibers are formed in flat-top or roller-top carding machines or the like as part of nonwoven or textile processes.
Poor crimp formation, especially in fibers with non-round cross-sections, has been associated with low and variable cohesion, weak webs, web separation, and poor processability during carding and/or subsequent operations. Relatively high lubricant levels and particularly those above 0.2 weight percent of certain processing lubricants can cause unsatisfactory cohesion and processability in carding.
Use of fluorescent agents for the tracing and identification of articles such as monitoring the integrity of the yarn or fiber during slashing, warping or weaving is described in U.S. Pat. No. 4,992,204. The patent discloses tagging a material with a luminophore that is cross-linked with at least one poly(oxyalkylene). The tagging compound has an absorbance within the range of about 300 mn to 400 nm.
Heretofore, fluorescent materials have substantially been used for security measures. For example, U.S. Pat. No. 4,504,084 issued to Miehe et al. on Nov. 12, 1991 discloses a method for marking originals so that copies can be distinguished from the originals. The method includes using a printing ribbon having a substance in the form of a marking which, when used, produces an invisible distinguishable mark which is recognizable only by using a special scanner.
In the co-pending patent application Ser. No. 09/303,338 entitled "FIBERS CONTAINING MARKER COMPOSITIONS AND CROSS-LINKED POLYMERS" filed on even date herewith, the entire disclosures being incorporated herein by reference, it is disclosed that certain near-infrared compositions can be applied and associated with fibers and fibrous materials by using cross-linking agents.
In some applications, removal of water is necessary using means known in the art prior to use of the treated fibers. In some applications, fairly rapid drying or evaporation of the carrier fluid is desired, which could make a water-soluble or water-dispersed coating unsatisfactory. In yet certain other applications, near-infrared markers dissolved or dispersed in water do not penetrate hydrophobic materials well.
Accordingly, there is a need for a marking compound that is substantially invisible to the unaided human eye in the ultraviolet and normal light wavelengths and which may be dried at a faster rate, a lower temperature and/or has a better penetration relative to such aqueous-based coating compositions.